In various industrial processes, it often is provided to gravity feed fine bulk material through ducts to various types of equipment including valves, mixers, grinders, screeners, storage vessels, receptacles and the like. Often such ducts are provided with various forms of barriers to prevent the passage of unintended items such as tools, machine parts, tramp materials and possibly interrupting or deterring the flow of the material being processed, contaminating such material, damaging downline equipment and potentially injuring operating personal. It has been found, however, that such prior art devices are not sufficiently effective in precluding the passage of a broad scope of undesirable objects or accommodating the removal of a number of such items. Accordingly, it is the principal object of the present invention to provide a device disposable in a duct conveying a fine bulk material which is effective in not only screening a greater form of articles but accommodating in the removal of a number of such articles.